Tibalt, Cosmic Impostor

As Tibalt enters, you get an emblem with "You may play cards exiled with Tibalt, Cosmic Impostor, and you may spend mana as though it were mana of any color to cast those spells."
+2: Exile the top card of each player's library.
−3: Exile target artifact or creature.
−8: Exile all graveyards. Add {R}{R}{R}.

Valki, God of Lies

When Valki enters, each opponent reveals their hand. For each opponent, exile a creature card they revealed this way until Valki leaves the battlefield.
{X}: Choose a creature card exiled with Valki with mana value X. Valki becomes a copy of that card.

Valki, God of Lies // Tibalt, Cosmic Impostor

Tibalt, Rakish Instigator

Your opponents can't gain life.
−2: Create a 1/1 red Devil creature token with "When this creature dies, it deals 1 damage to any target."

Tibalt, Wicked Tormentor

+1: Add {R}{R}. Draft a card from Tibalt, Wicked Tormentor's spellbook, then exile it. Until end of turn, you may cast that card.
+1: Tibalt, Wicked Tormentor deals 4 damage to target creature or planeswalker unless its controller has Tibalt deal 4 damage to them. If they do, you may discard a card. If you do, draw a card.
−X: Create X 1/1 red Devil creature tokens with "When this creature dies, it deals 1 damage to any target."

Tibalt, the Fiend-Blooded

+1: Draw a card, then discard a card at random.
−4: Tibalt, the Fiend-Blooded deals damage equal to the number of cards in target player's hand to that player.
−6: Gain control of all creatures until end of turn. Untap them. They gain haste until end of turn.